Haven't really watched any videos of the upcoming courses, just like what I did with Pack 1, so I can sort of experience them when I get the DLC. Hopefully when this pack releases, there wont be any issues uploading highlight reels.
I wonder if we'll get more DLC in the future (though I can only see there being 1 cup instead of 2 for potential future packs). In terms of characters, maybe 2 vets and 1 newcomer. If we are going to get more DLC after this, E3 would probably the most logical time to announce it. I wouldn't be surprised if Pack 2 is the last of the DLC though. We have a lot of content in the game. Definitely more than past games. Also, even if NX doesn't come out until 2017, they probably would want to start planning a Mario Kart for that system in the near future (a 2017 release would be great because that is the 25th anniversary of Mario Kart).